The purpose of this project is to document the clinical features of the Usher syndromes and to establish phenotype-genotype correlations for specific mutations in genes causing Usher syndromes types 1B and 1C. We have contributed to the localization of these two genes and are currently sequencing harmonin and myosin 7A in a large group of individuals with Usher>syndrome types 1 and 2 who have undergone precise ophthalmological, vestibular and audiological assessment. This information will be used to establish structure-function relationships for these genes and to improve the clinical diagnosis and treatment of the Usher syndromes.